Table 3.
Hormone | Linear regression of square root percent breast density on hormone levels | Mean percent density by hormone quartilea | P btrend | |||||
---|---|---|---|---|---|---|---|---|
β coefficient | SE (β) | P b | Q1 | Q2 | Q3 | Q4 | ||
Estradiol (pg/mL) | ||||||||
Age-adjusted | −0.0715 | 0.0158 | <0.0001 | 16.7 (14.1, 19.6) | 13.9 (11.4, 16.8) | 13.7 (11.2, 16.4) | 8.2 (6.1, 10.5) | <0.0001 |
Age and BMI adjusted | −0.0100 | 0.0169 | 0.55 | 13.8 (11.6, 16.3) | 13.6 (11.3, 16.2) | 14.1 (11.8, 16.7) | 11.1 (8.7, 13.8) | 0.25 |
Multivariable-adjustedc | −0.0102 | 0.0167 | 0.54 | 13.9 (11.6, 16.3) | 13.6 (11.3, 16.1) | 13.9 (11.6, 16.4) | 11.3 (8.9, 13.9) | 0.26 |
Free estradiol (pg/mL) | ||||||||
Age-adjusted | −2.50 | 0.523 | <0.0001 | 19.1 (16.2, 22.3) | 12.7 (10.4, 15.3) | 12.7 (10.4, 15.4) | 8.8 (6.7, 11.1) | <0.0001 |
Age and BMI adjusted | −0.25 | 0.584 | 0.67 | 15.4 (12.8, 18.3) | 11.9 (9.8, 14.3) | 13.6 (11.3, 16.1) | 12.1 (9.6, 14.8) | 0.22 |
Multivariable-adjustedc | −0.35 | 0.574 | 0.54 | 15.4 (12.8, 18.1) | 12.0 (9.9, 14.2) | 13.6 (11.3, 16.0) | 12.1 (9.7, 14.8) | 0.22 |
Bioavailable estradiol (pg/mL) | ||||||||
Age-adjusted | −0.0985 | 0.0206 | <0.0001 | 19.5 (16.6, 22.6) | 12.3 (10.0, 14.9) | 12.7 (10.4, 15.3) | 8.8 (6.7, 11.1) | <0.0001 |
Age and BMI adjusted | −0.0099 | 0.0230 | 0.66 | 15.8 (13.1, 18.6) | 11.6 (9.5, 13.9) | 13.6 (11.3, 16.1) | 12.0 (9.5, 14.7) | 0.17 |
Multivariable-adjustedc | −0.0137 | 0.0226 | 0.54 | 15.7 (13.2, 18.5) | 11.7 (9.6, 13.9) | 13.6 (11.3, 16.0) | 12.0 (9.6, 14.7) | 0.17 |
Estrone (pg/mL) | ||||||||
Age-adjusted | −0.0174 | 0.00661 | 0.01 | 16.1 (13.4, 19.1) | 12.0 (9.6, 14.6) | 14.2 (11.6, 17.0) | 10.5 (8.2, 13.2) | 0.02 |
Age and BMI adjusted | 0.0047 | 0.00652 | 0.47 | 13.7 (11.4, 16.2) | 11.2 (9.2, 13.5) | 14.6 (12.2, 17.2) | 13.6 (11.0, 16.4) | 0.60 |
Multivariable-adjustedc | 0.0041 | 0.00638 | 0.52 | 13.6 (11.4, 16.0) | 11.5 (9.5, 13.8) | 14.4 (12.1, 16.9) | 13.5 (11.0, 16.2) | 0.66 |
Estrone sulfate (ng/mL) | ||||||||
Age-adjusted | −0.447 | 0.325 | 0.17 | 14.2 (11.5, 17.2) | 14.6 (11.9, 17.5) | 12.7 (10.2, 15.4) | 11.6 (9.2, 14.3) | 0.11 |
Age and BMI adjusted | −0.049 | 0.292 | 0.87 | 13.0 (10.7, 15.5) | 14.5 (12.1, 17.1) | 12.8 (10.6, 15.2) | 12.7 (10.4, 15.2) | 0.65 |
Multivariable-adjustedc | −0.070 | 0.284 | 0.81 | 13.4 (11.1, 15.9) | 14.1 (11.8, 16.6) | 12.6 (10.5, 15.0) | 12.9 (10.6, 15.3) | 0.56 |
Testosterone (ng/dL) | ||||||||
Age-adjusted | −0.00974 | 0.00823 | 0.24 | 12.6 (10.1, 15.4) | 15.1 (12.3, 18.1) | 14.0 (11.4, 17.0) | 11.5 (9.1, 14.1) | 0.46 |
Age and BMI adjusted | −0.00810 | 0.00730 | 0.27 | 13.0 (10.8, 15.5) | 14.1 (11.7, 16.8) | 14.0 (11.7, 16.6) | 11.9 (9.7, 14.3) | 0.51 |
Multivariable-adjustedc | −0.00403 | 0.00719 | 0.58 | 12.6 (10.4, 14.9) | 14.1 (11.7, 16.7) | 13.9 (11.6, 16.5) | 12.5 (10.3, 14.9) | 0.96 |
Free testosterone (pg/mL) | ||||||||
Age-adjusted | −0.0971 | 0.0384 | 0.01 | 15.9 (13.1, 19.1) | 14.5 (11.9, 17.5) | 12.5 (10.0, 15.2) | 10.3 (8.1, 12.9) | 0.003 |
Age and BMI adjusted | −0.0387 | 0.0349 | 0.27 | 14.3 (11.8, 17.0) | 14.2 (11.8, 16.7) | 13.2 (11.0, 15.7) | 11.4 (9.2, 13.7) | 0.08 |
Multivariable-adjustedc | −0.0253 | 0.0340 | 0.46 | 13.7 (11.3, 16.2) | 14.1 (11.8, 16.5) | 13.6 (11.4, 16.1) | 11.7 (9.5, 14.0) | 0.23 |
Bioavailable testosterone (ng/dL) | ||||||||
Age-adjusted | −0.0396 | 0.0156 | 0.01 | 16.1 (13.2, 19.2) | 14.4 (11.7, 17.3) | 12.5 (10.0, 15.2) | 10.3 (8.1, 12.9) | 0.002 |
Age and BMI adjusted | −0.0158 | 0.0142 | 0.27 | 14.5 (12.0, 17.1) | 14.0 (11.6, 16.6) | 13.2 (11.0, 15.7) | 11.4 (9.2, 13.7) | 0.07 |
Multivariable-adjustedc | −0.0103 | 0.0139 | 0.46 | 13.8 (11.5, 16.3) | 13.9 (11.6, 16.4) | 13.6 (11.4, 16.1) | 11.7 (9.5, 14.0) | 0.21 |
Progesterone (pg/mL) | ||||||||
Age-adjusted | 0.0138 | 0.0040 | 0.0006 | 10.5 (8.4, 13.0) | 11.6 (9.3, 14.2) | 14.7 (12.1, 17.6) | 17.1 (14.0, 20.4) | <0.001 |
Age and BMI adjusted | 0.0096 | 0.0036 | 0.007 | 11.7 (9.7, 14.0) | 11.7 (9.6, 14.0) | 14.2 (11.9, 16.7) | 15.9 (13.3, 18.7) | 0.01 |
Multivariable-adjustedc | 0.0075 | 0.0035 | 0.03 | 11.9 (9.8, 14.1) | 12.0 (9.9, 14.3) | 14.1 (11.8, 16.6) | 15.4 (12.9, 18.2) | 0.02 |
Sex hormone binding globulin (nmol/L) | ||||||||
Age-adjusted | 0.0192 | 0.00390 | <0.0001 | 10.8 (8.5, 13.3) | 12.4 (10.1, 15.1) | 12.2 (9.8, 14.9) | 18.3 (15.3, 21.6) | 0.001 |
Age and BMI adjusted | 0.0068 | 0.00400 | 0.09 | 13.9 (11.4, 16.5) | 14.6 (12.2, 17.2) | 10.5 (8.4, 12.7) | 14.3 (11.7, 17.1) | 0.70 |
Multivariable-adjustedc | 0.0073 | 0.00389 | 0.06 | 13.5 (11.1, 16.1) | 14.5 (12.2, 17.0) | 10.6 (8.7, 12.8) | 14.6 (12.1, 17.3) | 0.98 |
SE standard error; BMI body mass index
aMean percent density displayed is reverse transformed from model of square root density
bP refers to the statistical test of the continuous hormone variable; Ptrend refers to the test for the ordinal variable representing hormone quartile in a separate model
cAdjusted for age (continuous), body mass index (continuous), parity (0, 1,2, 3+), vigorous physical activity (0–1.0, 1.1–4.0, >4.0 h/week), pack years of smoking (None, 1–15, >15), and family history of breast cancer (No, Yes)